1. Technical Field
The present invention relates to a physical quantity sensor and an electronic apparatus.
2. Related Art
In recent years, there have been developed physical quantity sensors such as an inertia sensor, for detecting a physical quantity using, for example, a silicon MEMS (micro-electromechanical system) technology.
For example, in JP-A-2008-544243 (Document 1), there is disclosed a capacitance physical quantity sensor for detecting the acceleration in a Z-axis direction (a vertical direction). In the physical quantity sensor of Document 1, a mass section is supported with torsional springs symmetrically with respect to the longitudinal direction of the mass section, and asymmetrically with respect to the thickness direction of the mass section.
However, in the physical quantity sensor according to Document 1, due to the influence of the stress caused by a difference in thermal expansion coefficient between a substrate (a wafer) forming the mass section and the torsional springs, and a seal member bonded to the substrate, the stress applied to the device when mounting the device, and so on, the characteristics such as a spring constant of the torsional springs are varied to thereby degrade the reliability in some cases.